The present invention is directed to a package for containing an organic solvent. Optionally, in addition to the solvent, the package may contain other materials dissolved in the solvent and/or a solid carrier such as cloth or the like that makes use of the solvent or solution contained in liquid form in the package more convenient. More particularly, the invention relates to a package made from a flexible laminated sheet material that is resistant to chemical interaction with most organic solvents.
Organic solvents, such as naphtha, acetone and various alcohols, are commonly used for cleaning hard surfaces to remove traces of dirt, grease and oils. Examples of various uses for organic solvents include the cleaning of electronic components prior to assembly, cleaning of medical instruments and cleaning of surfaces prior to applying a finish coating.
Cleaning solvents are generally used by the user by pouring an amount of the desired solvent onto an absorbent cloth or other applicator. The cloth or applicator is then rubbed onto the surface to be cleaned to remove foreign material. This approach often results in excessive amounts of the solvent being used. In addition, large amounts of the solvent are lost due to spillage and evaporation. In commercial applications, the time necessary to add the solvent to the applicator manually reduces production output and the loss of solvent increases the operating expenses to obtain the desired result.
To overcome the disadvantages of these methods of applying a solvent to a cloth by the user as needed, various prepackaged cloths or wipes have been produced. These prepackaged wipes typically include a flexible, absorbent sheet material containing a predetermined amount of a desired solvent. Most prepackaged wipes include an aqueous solvent system containing small amounts of various alcohols, humectants and moisturizers. Other solvent systems which have been used in prepackaged wipes include naphtha for cleaning metal surfaces prior to painting.
It is generally desirable to provide prepackaged wipes or towels in packages made from flexible plastic films to reduce the weight and bulk of material used to make the package and to provide simplified manufacturing procedures. Flexible containers or pouches also have the advantage of being collapsible so that as the contents are removed, the open end of the container can be folded over upon itself to reduce the overall volume of the container.
Containers and pouches made from flexible sheet materials are limited by the strength and durability of the sheet materials. Many sheet materials are not suitable as packaging materials due to their limited strength and bonding properties. In addition, the sheet materials used for the packaging of liquids must be non-reactive and impermeable to liquid and the vapors. This is of particular concern with containers for volatile or toxic solvents.
Sheet materials used for packaging materials are typically polymeric plastic films. Many polymers are soluble or swellable in certain organic solvents which limits their use in packaging organic solvents or materials, such as saturated wipes or towels, containing a solvent. Efforts to overcome the limitations of polymeric films include the manufacture of rigid containers which can contain pre-saturated wipes. Rigid containers have also been produced which contain dry wipes or towels where the ultimate consumer pours an amount of a desired solvent into the container to saturate the wipes or towels prior to use. These containers usually have a suitable outlet for removing the wipes from the container and a cover to close the container after each use.
Various laminated sheet materials have also been used for the manufacture of containers and pouches. Laminated sheet materials have the advantage of being able to include selected barrier layers to limit the permeability to certain compounds through the sheet. One example of such a package made from laminated sheet material containing saturated wipes is disclosed in U.S. Pat. Nos. 5,595,786 and 5,688,394 to McBride et al. These patents disclose a package made from nylon or a laminate of a polyester layer and a polyethylene layer. The packaging disclosed in these patents is limited by the solvent which can be contained in the package. Many solvents such as the naphtha described in the McBride et al. patents attack the laminates and cause separation and delamination of the polymeric film layers. These patents note that certain solvents cannot be used in packages made from the laminated film.
In view of the above-noted limitations and deficiencies of the prior packaging methods and materials, a continuing need in the industry exists for improved packaging.
A primary object of the present invention is to overcome and obviate at least one of the disadvantages and limitations of the prior packaging methods and containers. Accordingly, one embodiment of the present invention is directed to a package containing an organic solvent or solution where the package is economical, durable and convenient to use. Additional alternative objects of the invention, several of which are concurrently achieved by some of the preferred embodiments, are:
To provide a package that is convenient and economical to manufacture from a multi-ply laminate that is resistant to attack and delamination by most organic solvents.
To provide a flexible package for transporting and dispensing organic solvents and particularly volatile organic solvents.
To provide a resealable package containing a plurality of carrier sheets containing an organic solvent contained within the carrier sheets.
To provide an effective package for minimizing the release of volatile organic compounds into the atmosphere.
To provide a flexible package for aggressive organic solvents, such as alcohols, ethers, esters and acetates that cannot normally be packaged in containers made from polymeric films.
To provide a method of cleaning a hard surface using a carrier sheet containing an organic solvent, where the carrier sheet and solvent are dispensed from a resealable, flexible package.
To provide a convenient method and article for applying to a solid surface a liquid particularly adapted to xe2x80x9chighlightingxe2x80x9d any small blemishes in the uniformity of the finish of the solid surface.
To provide a convenient method and article for applying to a solid surface a film of liquid that will prevent the adhesion to the surface of hot metal particles, such as those commonly known as xe2x80x9cweld splatterxe2x80x9d that are introduced into the ambient atmosphere during conventional arc welding.
To provide a package of pre-saturated carrier sheets containing a volatile organic solvent where the carrier sheets can be removed from the package and the package reclosed to prevent evaporation of the solvent remaining in the package.
The objects and advantages of the invention are basically attained by providing a reclosable package comprising a flexible, laminated sheet material folded to form the package, which has a bottom wall and first and second side walls each having a top end. The side walls have longitudinal side edges which are attached together along the side edge of the opposing side wall. The bottom wall is folded to form a gusset extending transversely to the side edges of the bottom wall. The bottom wall is attached to the respective side wall along a seal line extending diagonally from the side edge of the side wall to the bottom edge of the side wall. The side edges of the bottom wall in some embodiments are also attached to the side edges of the side walls to form a closed bottom container. The laminated sheet material is preferably a sheet material having an outer ply of polypropylene and an inner layer of a metal foil. The polypropylene is particularly desirable since it is resistant to chemical interaction and enables the edges of the side and bottom walls to be heat sealed together.
The package sometimes contains at least one and preferably a plurality of porous carrier sheets of suitable material or other applicators carrying an organic solvent or solution, which may be a single chemical substance or a mixture or two or more chemical substances, absorbed in the carrier sheet. The solvent or solution includes at least one chemical substance selected from the group consisting of ketones, esters, ethers, alcohols, hydrocarbons, glycol ethers and esters of glycol ethers, and unsubstituted hydrocarbons. A closure member is attached to the top end of the package for closing the package after removing one or more of the carrier sheets.
The objects and advantages of the invention are further attained by providing a package comprising a flexible sheet material folded to form a package having first and second sides, a bottom end and top end, the sheet material being a laminated metal foil having an outer polypropylene face forming an inner surface of the package. The package contains at least one organic solvent substance as detailed in the preceding paragraph. The sheet material used to form the package is resistant to attack and delamination by the solvents.
Some objects, advantages and other salient features of the invention will become more apparent in view of the following detailed description of the invention and the annexed drawings which form part of this original disclosure.